Singh Pankaj K, Hollingsworth Michael A
Eppley Institute for Research in Cancer and Allied Diseases, Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-6805, USA.
Trends Cell Biol. 2006 Sep;16(9):467-76. doi: 10.1016/j.tcb.2006.07.006. Epub 2006 Aug 9.
Mucins are heavily glycosylated high molecular weight glycoproteins, which are involved in the protection and lubrication of luminal epithelial surfaces. Transmembrane mucins also engage in signal transduction, through extracellular domain-mediated ligand binding or by interacting with receptors for growth and differentiation factors. The cytoplasmic tail of MUC1 (MUC1CT), the best characterized of the transmembrane mucins, is involved in several signaling pathways, including those involving Ras, beta-catenin, p120 catenin, p53 and estrogen receptor alpha. MUC1CT also forms complexes with transcription factors, and then translocates to the nucleus by an unknown mechanism, where it is believed to influence the transcription of their target genes. MUC1CT has also been proposed to localize to mitochondrial membranes under conditions of genotoxic stress, where it attenuates the apoptotic pathway in response and confers resistance to apoptosis-inducing drugs.
粘蛋白是高度糖基化的高分子量糖蛋白，参与管腔上皮表面的保护和润滑。跨膜粘蛋白还通过细胞外结构域介导的配体结合或与生长和分化因子的受体相互作用参与信号转导。MUC1（MUC1CT）是特征最明确的跨膜粘蛋白，其细胞质尾部参与多种信号通路，包括涉及Ras、β-连环蛋白、p120连环蛋白、p53和雌激素受体α的信号通路。MUC1CT还与转录因子形成复合物，然后通过未知机制转运到细胞核，据信在细胞核中它会影响其靶基因的转录。也有人提出，在基因毒性应激条件下，MUC1CT定位于线粒体膜，在那里它会减弱凋亡途径并赋予对凋亡诱导药物的抗性。
